Streaming media refers to multimedia content such as audios or videos by means of data stream issued on the Internet in real time. The streaming media technology refers to compressing and encoding a whole multimedia file into multiple compressed packages, and sequentially transmitting the multiple compressed packages to a client in real time, so that a user is capable of decompressing and playing a downloaded compressed package while downloading a subsequent compressed package, thereby saving time.
According to the existing HTTP Streaming protocol, a multimedia file which is sliced by a content preparation unit is encapsulated into media fragments conforming to a required format and description information about each media fragment is generated, and then, the media fragment and the description information about each media fragment are pushed to an HTTP Streaming server, where the description information about the media fragment describes content of the media fragment, a multi-code rate, and request address construction information of the media fragment. The HTTP Streaming server stores the media fragment, the description information about the media fragment, and responses media fragment request information from the client. The media fragment request of the client includes information such as a code rate, resolution and language of the requested media fragment. The code rate of the media fragment requested by the client is dynamically adjusted by the client according to the bandwidth of the client. If the client is in low bandwidth, the client requests the HTTP Streaming server for a low-code-rate media fragment; if the user is in high bandwidth, the client requests the HTTP Streaming server for a high-code-rate media fragment.
In a fixed network, a bandwidth resource relatively constant, the HTTP Streaming server can provide media fragments with different code rates according to different bandwidth resources, and code rate adaptation between the client and the HTTP Streaming server is relatively simple. However, for a wireless network, because an air interface resource changes continuously, the code rate adaptation needs to be performed on the code rate of the media fragment according to the change of the air interface resource.
Because each client can merely learn its own link situation when measuring its own bandwidth and adjust the code rate of the requested media fragment according to its own link situation, but cannot rationally utilize resources of a whole cell, which affects a throughput of the whole cell.